Printer; Imaging Subsystem; Xerographic Subsystem - Xerox DocuPrint 180 Product Manual

Printer

Imaging subsystem

Xerographic subsystem

XEROX DOCUPRINT 180 LASER PRINTING SYSTEM PRODUCT GUIDE
The printer contains the imaging, xerographic, and output
subsystems.
The imaging subsystem accepts a formatted page of data from the
system controller (forms and graphics have already been merged) for
the xerographic process.
One of the important keys to DocuPrint 180 LPS print quality lies in
the xerographic process itself. The print image produced by the dry
ink is very dark to create more contrast between the printing and the
page, making images easier to read.
The following steps describe the xerographic process:
Step 1. A band full of video data (1s and 0s) is transferred from the band
buffer to the laser scanner.
Step 2. The laser beam moves across the surface of the photoreceptor belt
based on the value of the incoming bit (1 or 0), producing a latent
image.
In this step, a charge is applied to the surface of the photoreceptor
belt. The surface is discharged when it is exposed to the laser beam,
thus creating a pattern of dots corresponding to the page that is to be
printed.
Step 3. The photoreceptor belt is then exposed to dry ink. The dry ink clings
to the pattern of dots corresponding to the page that is to be printed.
Step 4. A sheet of paper traveling along the paper path is brought into
contact with the surface of the photoreceptor belt. The dry ink is then
transferred from the photoreceptor belt onto the paper.
Step 5. The paper carrying the pattern of dots passes through a fusing
mechanism that permanently affixes the dry ink to the paper.
Step 6. The finished page is deposited in the output tray or bin. The data
from that page is erased from memory. The photoreceptor belt is
then cleaned and prepared for the next page.
Resolution An DocuPrint 180 LPS imaging system converts a character from
digitized form into a printed image composed of tiny dots. These dots
are so small and close together that they appear to form solid black
areas. Image clarity is determined largely by the resolution or the
number of dots per inch printed. Within the Xerox DocuPrint 180 LPS
Reference Set, the terms spots, dots, and pixels are used
interchangeably.
The Xerox DocuPrint 180 LPS accepts 300 dots per inch (dpi) print
data and images and electronically modifies them to produce 600 dpi
print resolution. 600 dpi input print data is not accepted by the Xerox
DocuPrint 180 LPS for printing. References to 300 dpi or 600 dpi
apply to both coordinate axes (300 by 300 dpi or 600 by 600 dpi).
BASIC CONCEPTS
2-3